Conventionally, there have been proposed a variety of radio network systems in which a plurality of radio terminal stations are connected to each other via radio communication lines.
There is proposed a first-type radio network system, in which a control station has been determined in advance and thus previously determined control station manages communication among respective terminal stations. In this case, the control station works as a semipermanently fixed connection point called as an access point, which manages communication among respective terminal stations included in a radio network. Thus, in general, the configuration of the control station being an access point is different from those of other terminal stations.
There is also proposed a second-type radio network system called the ad hoc type radio network. The ad hoc type radio network is composed of a plurality of communication apparatuses which can communicate with each other. There is no specified access point in the ad hoc type radio network, and each of the communication apparatuses included in the radio network can make a connection with other communication apparatuses freely. Each of the communication apparatuses included in the ad hoc type radio network has the function of working as a control station, and all of the communication apparatuses may have the same configuration.
There is further proposed a third-type radio network system which is composed of a plurality of communication apparatuses, in which any of the plural communication apparatuses is caused to have the function of a control station. For example, any of the communication apparatuses is selected as a control station, and thus selected communication apparatus manages transmission resources.
In the first-type radio network system using a control station settled as an access point, it is difficult to construct a network freely since the access point is located at a semipermanently fixed position. For example, it is difficult for a terminal station which is located far away from the control station to enter into the radio network system since the terminal station cannot receive control signals from the control station. Furthermore, in the first-type radio network system, the configuration of the control station as an access point is different from those of other terminal stations. So, it is impossible to utilize a terminal station, other than the control station, as a control station.
Furthermore, in the first-type radio network system, in case of dividing a radio network into two or more radio networks, it is necessary to properly relocate control stations as access points at respective reconstructed radio networks. Also, it is necessary for respective relocated control stations in respective reconstructed radio networks to redo network management such as registration of newly connected terminal stations. Thus, there is undesirably raised complicated processing.
On the other hand, in the second-type radio network system of the ad hoc type, it is difficult to unitarily manage transmission line resources when respective communication apparatuses perform band reservation transmission since there exists no specified control station. Also, it becomes difficult to unitarily manage temporal resources when respective communication apparatuses perform time-division multiplexing transmission.
On the other hand, in the third-type radio network system using any of plural communication apparatuses as a control station, when a communication apparatus is automatically selected as a control station of the radio network, a communication apparatus, not desired by the user, may be selected as a control station since the communication apparatus is selected by simply comparing processing capability of the respective communication apparatuses. In this case, there is raised a problem that a network desired by the user cannot be constructed freely or an undesirable network which the user does not desire may be constructed.
Furthermore, in case there exist several communication apparatuses each of which can work as a control station in a communication space, there are undesirably constructed plural networks, and a problem is raised that one communication apparatus is included in a first network and another communication apparatus is included in a second network.